Er:YAG Laser Ablation of Bone versus Conventional Burrs in Otologic Surgery

Abstract

Objectives:

The Er:YAG laser (EYL) provides an efficient means of precise and predictable bone ablation, without intense thermal injury associated with CO2 laser use. Use of the EYL in otology is possible, but must be undertaken with caution as ablation is associated with brief intense acoustic transients up to 120 dB. This study details the use of the EYL in otologic and neuro-otologic surgery and compares ablation using a commercially available EYL with customizable glass fiber tips versus diamond and cutting burrs by means of infrared thermal imaging (IRT) and environmental scanning electron microscopy (ESEM).

Methods:

Five 0.6 mm diameter cylindrical cuts to a depth of 0.6 mm were made in formalin fixed human squamous temporal bone using a 300 µs EYL with pulse energies of 250 and 400 mJ (corresponding fluence levels of 175 and 280 mJ/cm2) and 0.6 mm diameter cutting and diamond burrs. Copious irrigation was used for all cuts. IRT was used to determine temperature rise. Ablation regions were inspected with ESEM.

Results:

Peak temperature rises were similar for all methods of ablation, none exceeding the 12 °C threshold required for irreversible bone injury. ESEM revealed rough margins for cuts made using the cutting burr and smooth edges with no sign of microfracture for those made with EYL and diamond burr.

Conclusions:

EYL ablates bone efficiently and predictably with smooth margins without microfractures or clinically significant temperature rise. When used appropriately, EYL may be a valuable tool for the otologic surgeon.